Carbon dioxide system



Feb. 23, 1943;- c. H. LINDSAY CARBON DIOXIDE SYSTEMS Filed Feb. 3, 1940 INVE TOR.

ATTO

.Patented Feb. 23, 1943 CARBON DIOXIDE SYSTEM Charles H. Lindsay,

American-La France-Foamite Corporation,

Elmira, N. Y., assignor to mira, N. Y., a corporation ot New York Application February 3, 1940, Serial No. 317,075

Claims.

The invention is a carbon dioxide discharge system such as used for tire-extinguishing purposes and more especially for the nre-extinguishing systems of aircraft, though not limited to any particular use. The purpose is to insure maximum discharge efficiency under all possible conditions of use; that is to say, in all positions in which the system may be put when called into action. To this end, the invention consists in a particular construction of the outflow conduits within the flask in which the carbon dioxide, in liquid form, is stored, the same being so ldesigned as, in all positions, to postpone outow of the contents in its vapor phase until substantially all of its liquid phase has rst passed out. This insures that the entire contents will be evacuated without freezing or snow formation likely to clog the discharge passages. I

The invention can be, and preferably is, incorporated in the dip-tube member, sometimes called syphon tube, with which carbon dioxide flasks are commonly equipped and is so shown in the drawing wherein Fig. l is a longitudinal section of a conventional flask containing the new dip-tube, Fig. 2 is an enlarged section of the connector tting thereof and Fig. 3 a similar section of the terminal fitting thereof.

The iask l is normally closed by a screwed-in operating head 2 which includes a sealing disc 3 adapted to be pierced and opened in time of fire by a cutter 4 so that the contents of the ask may escape through theoutlet 5. The means, automatic or manual, for operating the cutter are omitted from the drawing.

The dip-tube 6 consists in the present case, and preferably, of a length of flexible metallic tubing as distinguished from the rigid pipe generally employed. Being flexible, its free end can rest on the lower side wall of the ask and submerge itself in any liquid present in all. positions in which the ask base is lower than the head. The exibility is not suiiicient to permit the free end to become submerged when the iiask is inverted.

The dip-tube is connected to the discharge head 2 by means a coupler fitting 1, so that it becomes a continuation of the bore of the head and therefore it is a part of the outflow path. Its free end is provided with an inlet iitting which is a valve cage containing, preferably, a ball or gravity valve 9 and provided with a series of inlet passages l0. 'I'he valve seats against' the entrance to the tube that isto say, it closes with the flow and the interior of the cage is coned or tapered so that when the ask and cage lie in horizontal positions the ball rolls away from its seat, thus opening the path through the tube. The angle of the taper is predetermined at about 5 so as to keep the ball from being swept to its seat by the inow of liquid into the tube in this position. Thus this valve remains open so long as the iiask is upright or inclined from vertical not more than about 90, and is closed in all other positions.

'I'he coupler fitting 1 contains or is provided with an outwardly-closing inlet valve Il, also shown as a ball, held in a cage I2 which is pressed or soldered into the side of the fitting. This ball is urged to its seat by a light spring i3. It closes counter to the direction of flow.

When the flask is upright or within 90 of that position and the sealing disc is opened by means of the cutter 4, liquid dioxide from the lower part of the flask, being of course under great pressure, flows upwardly past the valve 9, through the iiexible tube and out through the discharge outlet 5. The pressure of this stream supplements that of the spring I3., on the check valve Il, so as to keep this valve closed during this flow, which prevents outflow of any of the dioxide in vapor phase from above the liquid level. Thus the liquid is rst to pass out and when it has all gone, or substantially all gone, the vapor phase being still under pressure follows it, making a complete discharge. When the flask assumes a posture in which its discharge head is lower than its base and the liquid therein occupies the normally-upper end of the flask, the inlet cage willv be in the vapor and ball 9 will close by gravity, so that none of such vapor can enter the diptube. At such time the valve Il opens under the pressure of the liquid in which it is then submerged and such liquid iiows through the tting and out of the iiask. preceding the vapor as before. 'Ihus in any posture, the ask is completely and perfectly discharged. It is explained that if a. considerable portion of the dioxide vapor is allowed to escape from the flask ahead of the dioxide liquid, the consequent reductionK of the internal pressure induces vaporization of the liquid at such a rate as to freeze it solid in the flask, thereby preventing its useful applicationto the flre. This effect is avoided by 'the new system of which further advantages are,

that it is impossible for discharge to-be pre.

vented by the simultaneous closure' of both valves, since one of them opens by the dioxide pressure, and that weight and material are conserved, important in aircraft systems, by locating one of the two valves at the free end oi the flexible section 6 Where its weight takes the place of the weight-bob usually flxed to flexible dlptubes to help them fall to the low point of the having two relatively remote entrances to said passage, a gravity valve controlling the flow through one entrance, said valve closing in the direction of flow and a spring-seated valve controlling the flow through the other entrance, said latter valve opening in the direction of flow.

3. A container of liquefied gas under pressure adapted to discharge liquid either end up, having means constituting a discharge passage and provided with two` entrances to said passage, means for controlling the ilow through one of said entrances comprising a gravity valve adapted to close by movement in the direction of Ilow, said valve including a cage and a ball, said cage having an interior ball-supporting surface sloped at about to the axis thereof, and a valve controlling the other entrance. said latter valve being resiliently urged to its seat and opening by movement in the direction of Ilow.

4. A container of liquid under pressure, intended to discharge liquid either end up, having a discharge head screwed directly into its neck portion and a dip-tube structure Within the container in communication with such head, said tube having two entrances, one entrance .being located near one end of the container and the other near the opposite end, and a valve controlling the oW through each of said entrances,-

one of said valves being adapted to open by the pressure thereon of the fluid in the container, and the other being adapted to open and close by the effect of gravity.

5. A container of liquid under pressure adapted to discharge liquid either end up and having a' discharge head screwed directly into its neck opening, a dip-tube structure within the flask constituting part of a discharge passage extending through said head, said structure having two entrances into said passage remote from each other, a gravity operated valve controlling flow through one of said entrances and a springseated valve controlling flow through the other, said latter valve opening in the direction of ilow.

(i. In a container of liquid under pressure a flexible dip-tube constituting part of the liquid outflow passage of such container, said tube being weighted at its free end by a valve structure attached thereto and controlling the ilow into it.

7. In a container of liquid under pressure to be discharged either end up, a flexible dip-tube forming part of, the outlet passage from the container, a weight on the free end of such flexible tube in the form of a valve'cage with a gravity valve member therein controlling the flow into such end of the tube, said passage having another entrance remote from said free end of the tube 20 and a second valve controlling the flow through said entrance into said outlet passage.

8. A flask of liqueed gas having a disc-sealed discharge head occupying and normally closing its neck opening, a coupler on the head within the flask, a flexible dip-tube connected to the head by the coupler, a valve structure attached to the free end of the flexible dip-tube and serving as a weight therefor, and another valve housed in said coupler. 9. A carbon dioxide discharge system comprising a ilask having a discharge head and a ilexible dip-tube in communication therewith and provided with two relatively remote entrance ports, a gravity valve adapted to close one of said ports in all positions in which the flask axis is tipped to more than about 90 from upright, a valve for the other port closing counter to the ilow adapted to prevent flow toward said head when the position of the axis is less than 90, and a spring for closing said latter valuve.

10. A flask of liquefied gas or like fluid under pressure having a discharge head screwed into its neck and normally closing the same, a coupler adjacent the narrowed or neck part of the flask, a dip-tube connected with the head by means of said coupler,'said head, coupler and tube constituting the discharge passage for the flask and being provided with two relatively remote entrances into it, valves Within the flask for respectively controlling said'entrances, one of said valves being contained in said coupler and a spring for closing said valve acting against the flow into said passages.

CHARLES H. LINDSAY. 

